Hello spywar,
Real-time protection
Don't know much about Comodo but I'm sure that it is enough if you have all the seetings configured away that you like.
Browser protection
It's essentials to know as much as possible about the web pages that you are visiting, in order to avoid different type of attacks.
I would recommend that you install a site advisor like Web of Trust which will greatly help you, while online.
WOT (Free) -
link
To help you avoid malicious sites you can use Web of Trust (WOT) a website rating browser plugin. After you add it to your browser make sure you only visit websites rated "Green" by WOT
You can also add a password manager for your browser,which should make your life on the internet a lot more safer and easier.
LastPass (Free) -
link
LastPass is an online password manager and form filler that makes web browsing easier and more secure
Virtualization:
Even if you submitted a file to virustotal.com and it said that it's clean , you'll need to run it in virtual environment because sometimes infection can be so new that security vendors don't have signs for it.
Virtualization software will allow you to browse the web or run another application in a completely safe environment. This is especially useful when visiting high-risk web sites, whether accidentally or deliberately, as the Web browser will be completely contained within the virtual enviroment, preventing any damage to your computer.
A sandbox can also be used to run any other applications which you think may be suspect - you can run the program inside the sandbox to determine whether or not it is safe while remaining completely protected against any malicious actions that it may try to carry out.
I strongly advise you to install Sandboxie and use it when you're browsing the Internet or running shady/unknown programs.
Alternately you can try
BufferZone PRO (Free) , another great virtualization software.
Sandboxie (Free/Paid) -
link
Sandboxie runs your programs in an isolated space which prevents them from making permanent changes to other programs and data in your computer.
Always run suspicious of freshly downloaded files in a Sandboxie to verify that he download isn't compromised!Sandboxie will replicate perfectly your operating system so all the files should run without any problems in it.
Extra protection:
Because you are using a slightly older operating system which is slightly targeted by cyber criminals ,you can install the below program to prevent the exploit of different vulnerabilities that your system might have.
EMET 2 (Enhanced Mitigation Experience Toolkit) (Free) -
link
EMET provides users with the ability to deploy security features built into Windows to arbitrary applications. This helps prevent vulnerabilities in those applications from successfully being exploited. DEP, SEHOP and ASLR are such security features, if you want to learn more about what they do, you can watch this
video from Microsoft TechCenter. To configure EMET you should follow this
guide by rationallyPARANOID.
Backup:
Since you don't have a backup I thought I might give you a couple of suggestions.